Regarding your first point -- Jesus makes clear the way we should live our lives by his words and his actions. He is compassionate and, as you mentioned, demands that we do unto others as we would have them do unto us especially if we don't want to for whatever reason. He made an example of this multiple times by conversing with schismatics, gentiles, prostitutes, tax collectors etc Through his love these people repent of their sins. God loves us but demands we have faith and earnestly try to obey his commandments if we want to enter the Kingdom of God.
Also I don't see how you are using Leviticus 20 to say homosexuality (specifically acting on same sex attraction) is not a sin. It says the exact opposite.
If a man lies with a male as he lies with a woman, both of them have committed an abomination. They shall surely be put to death. Their blood shall be upon them.
Romans 1:26-27 also calls out homosexual acts between men as sin.
Homosexuality is not a sin and no scripture supports such an interpretation. Paul’s letters also do not support such an interpretation. Any scripture used to defend such an anti-Christ stance is a gross and deliberate mistranslation.
You've provided no justification while disagreeing with over 2000 years Christian teachings. Which church do you attend?
What Jesus also taught is to live by example, not to judge others, and to not worry about what you perceive other’s shortcomings to be. (Matthew 7)
Sure. I try and fail everyday to live up to the standards of Christ. Such is the life of a Christian. When I speak about Churches failing I'm not happy about it. I legitmately sympathize. When I talk about homosexuality being a sin I'm not puffing up my chest. I feel empathy for people who are either ignorant of or struggling with that lifestyle. Furthermore as a sinner I am in the same boat. My sins are different but every bit as sinful. I pray daily for the mercy of God.
Also: “Hate the sin, but love the sinner” is not scriptural. It is a corruption of a saying from Augustine, Bishop of Hippo: “with love for mankind and hatred of sins.”
The two phrases literally mean the same thing. It is scripturally based. Christ loves us but hates our sin. Christ died on the cross for our sins. We must accept Christ and work daily to abide by his commandments.